Detection of angular momentum of electrons also called “spin” is important within the field of spin electronics and applications such as spintronics.
Current spin-detectors operate with Mott scattering, spin-LEED, or the exchange scattering method. These methods and other existing but rarely used methods have very low transmission. The transmission of devices, including spin-including detectors, based on Mott scattering or spin-LEED are typically in the order of 10−3 and in addition has a rather low so-called Sherman function, typically around 0.2. In addition, the existing solutions do not enable parallel detection of spin, momentum and energy. This is in stark contrast to modern hemispherical analyzers for spin integrated photo emission that are two-dimensional and measure a range of energies and angles in parallel.
Spin-detectors are usually classified according to a so-called figure of merit defined asG=I/I0*Seff2 where I/Io is the proportion of incoming electrons being detected. Seff is how true the detection is with respect to spin. An ideal detector has G=1, but typically G is in the range 10−3-104 for all existing detectors except the so-called “magnetic film diffraction detector”, which has shown a figure of merit exceeding 10−2. All these existing detectors can however only detect one electron at a time. In case of photoelectron spectroscopy for example, they operate by measuring the spin asymmetry for a single energy and angle at a time. This makes the figure of merit for existing detectors practically being close to 10−8. It is this low figure of merit that has prevented spin-resolved electronscopy from becoming more widely used in practice.
Thus, there has been a long-felt need to provide spin-detectors having higher transmission, higher Sherman function and thus higher figure of merit.